1. Field of the Invention
This invention relates to a method for the production of a silicate interlayer cross-linked smectite having a desired interlayer interval. The interlayer cross-linked smectite is expected to find utility as a catalyst, a catalyst carrier, an adsorbent, a separating material, etc. Needs are felt for the use in practical applications of various species of cross-linked smectite having various silicate interlayer intervals.
2. Prior Art Statement
The structure of interlayer cross-linked clay will be described below with reference to the accompanying drawing.
In the drawing, pillars 2 of alumina or zirconia intervene between two silicate layers 1 and micropores 3 are present between the two silicate layers which are kept apart by the pillars 2. The distance between the silicate layers is called an interlayer interval 4. No technique has been established to date for the control of this interlayer interval 4.
The interlayer interval of the interlayer crosslinked clay equals the height of pillars supporting the upper silicate layer as observed in the drawing. The interlayer interval is varied proportionately to a change in the height of the pillars. For the production of the interlayer cross-linked clay, a method which comprises introducing a cationic hydroxide oligomer such as of aluminum or zirconium into the space intervening between clay layers of hectorite or montmorillonite by means of ion exchange has been known to the art, for example, R. Setton(ed.), Chemical Reactions in Organic and Inorganic Constrained Systems, pp. 151-164, 1986; S. Yamanaka and G. W. Brindley, Clays and Clay Minerals, vol 27, No. 2, pp. 119-124, 1979. The interlayer interval of the interlayer cross-linked clay which is produced by this method is about 0.8 nm because it is based on the size of the cationic hydroxide oligomer.
The inventors have continued a study for the purpose of developing an interlayer cross-linked clay having a larger interlayer interval and have consequently succeeded in producing an interlayer cross-linked clay having an interlayer interval of at least 20 .ANG. (U.S. Pat. No. 4,629,713, and Japanese patent publications No. 62-12172, No. 62-41167, No. 62-46489, No. 62-46490, etc.). The clay is characterized by having a water-soluble macromolecular compound coexisting in the clay.
In the practical field, a desire has been expressed for the development of a method capable of producing an interlayer cross-linked clay having an interlayer interval desired to meet the purpose of use.
This invention aims at meeting the aforementioned desire and is directed to a method for the production of an interlayer cross-linked clay having a desired interlayer interval. The interlayer interval, particularly that in the range of 0.1 nm to 2.5 nm, can be controlled with ease.